1. Field of the Invention
The invention relates generally to a method and a system for coordinating protocol stack entities to share a single radio resource.
2. Description of the Related Art
A subscriber identity module (SIM) on a removable SIM card securely stores the service-subscriber key used to identify a subscriber on mobile stations (such as computers and mobile phones). The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or telephony device.
For a protocol stack (PS) entity executed in a mobile station comprising a single SIM card and a single Baseband/radio-frequency (RF) module, the mobile station is able to provide telephony services on the SIM card. In another case, for two protocol stack entities executed in a dual-USIM-supported mobile station comprising two universal SIM (USIM) cards and only one Baseband/RF module, the dual-mode mobile station is able to remain at a STANDBY mode for both USIM cards, and enter a TALKING mode or dial-up service for one of the USIM cards. In the STANDBY mode, the single Baseband/RF module may be utilized to listen to both paging occasions from the two USIM cards. However, when one of the USIM cards is in the TALKING mode or dial-up service, the hardware resource (Baseband/RF module) will be fully occupied, restricting another protocol stack entity from utilizing the hardware resource at the same time.